Artificial hip joint

ABSTRACT

AN ARTIFICIAL HIP JOINT IS PROVIDED HAVING AN ACETABULUM PROSTHESIS OF THE COTYLOID CAVITY DEFINING A SOCKET AND HAVING A PLURALITY OF BLADES EXTENDING OUTWARDLY AWAY FROM THE SOCKET FOR ENGAGING THE PREPARED WALL OF THE COTYLOID CAVITY. A PROSTHESIS OF THE HEAD OF THE FEMUR IS MOVABLY INTERCONNECTED WITH THE ACETABULUM PROSTHESIS AND INCLUDES A PIN TO BE DRIVEN INTO THE BONE-MARROW CHANNEL OF THE FEMUR, A CURVED NECK INTEGRAL WITH THE PIN, AND A HIP BALL FIXEDLY POSITIONED ON THE NECK AND MOVABLY LOCATED WITHIN THE SOCKET, THE SOCKET ENVELOPING MORE THAN ONE-HALF OF THE HIP BALL TO PREVENT WITHDRAWAL OF THE HIP BALL FROM THE SOCKET.

Sivash [11] 3,820,167 [451 June 28, 1974 ARTIFICIAL HIP JOINT Konstantin Mitrotanovich- Sivash, ulitsa Bolshaga Pirogovskaga 37/43-A, kv. 49, Moscow, USSR.

Filed: I Oct. 14,1971 Appl. No.: 189,261

Related US. Application Data C ontinuation-in-part of Ser. No. 737,910, June [8, 1968, abandoned.

Inventor:

US. Cl. 3/1, 128/92 CA Int. Cl. A6lf 1/24 Field of Search 3/1; 128/92 C, 92 CA, 92 F,

128/92 B-92 BC, 92 R References Cited UNITED STATES PATENTS FOREIGN PATENTS OR APPLICATIONS l24,585 3/1959 U.S.S.R l28/92 C l,047,640 7/l953 France 128/92 C OTHER PUBLICATIONS Vitallium Surgical Appliances (catalog), Austenal Laboratories, Inc., New York-Chicago, 1948, page 4.

A Metallic Fermoral Head Prosthesis for the Hip Joint by Earl .D. McBride, Reprint from The Journal of the International College of Surgeons, Vol. XV, Apr. 1951, N0. 4, pages 498503.

Primary ExaminerRichard A. Gaudet Assistant Examiner Ronald L. Frinks Attorney, Agent, or FirmWaters, Roditi, Schwarz & Nissen An artificial hip joint is provided having an acetabulum prosthesis of the cotyloid cavity defining a socket and having a plurality of blades extending outwardly away from the socket for engaging the prepared wall of the cotyloid cavity. A prosthesis of the head of the femur is movably interconnected with the acetabulum prosthesis and includes a pin to be driven into the bone-marrow channel of the femur, a curved neck integral'with the pin, and a hip ball fixedly positioned on the neck and movably located within the socket, the socket enveloping more than one-half of the hip ball to prevent withdrawal of the hip ball from the socket.

ABSTRACT 47 Claims, 6 Drawing Figures PATENTEUJUH28 1 14 7 3820.161

SHEET 2 UF 2 ARTIFICIAL HIP JOINT This application is a continuation-in-part of application Ser. No. 737,910, filed June 18, 1968, and now abandoned for Artificial Hip Joint.

The present invention relates to artificial joints and more particularly to an artificial hip joint.

Numerous types of artificial hip joints have been developed and are being used. These joints have been made with various types of materials in attempts to provide both a strong joint and one that will not be unduly corroded by the body environment. Various styles and arrangements of artificial hip joints having an artificial acetabulum articulately connected to an artificial caput femoris have been developed; however, use of these joints has made evident inherent disadvantages due to the shapes of the hips and to the materials used. Bone growth stimulated by the mechanical irritation of the artificial joints has also resulted in partial immobilization of the joints with a concomitant gradual increase of painful sensations.

Accordingly, it is an object of the present invention to provide an artificial hip joint that will provide all of the functions inherent in a normal human hip joint and which possesses great strength and service life.

Another object is to provide an artificial hip joint that is light in weight.

A further object of the invention is the provision of an artificial hip joint that avoids immobilization due to undesirable fibrous and bone growths around the joint.

Still another object is to provide an artificial hip joint which advantageously utilizes the normally undesirable fibrous and bone growths to assist in holding the joint in position within the body.

Still another object of the present invention is the provision of an artificial hip joint which is relatively simple and inexpensive to manufacture and which is relatively easy to insert into the body.

Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages are realized and attained by the instrumentalities and combinations particularly pointed out in'the appended claims.

To achieve these and other objects the present invention provides an artificial hip joint having an acetabulum prosthesis of the cotyloid cavity defining a socket and having a plurality of blades extending outwardly from the socket for engaging the prepared wallof the cotyloid cavity, and a prosthesis of the head of the femur movably interconnected with the acetabulum prosthesis and including a pin to be driven into the bone-marrow channel of the femur, a curved neck integral with the pin, and a hip ball positioned on the neck and movably located within the socket, the socket enveloping more than one-half of the hip ball to prevent withdrawal of the hip ball from the socket.

As here embodied, predetermined ones of the acetabulum blades have holes therein for enabling growth of bone tissue through the holes and around the blades for holding the acetabulum prosthesis in position within the body. In addition, the acetabulum prosthesis preferably includes two inserts, each of the inserts having a surface area for contacting the hip ball over more than one-fourth of the spherical surface area of the hip ball. The acetabulum prosthesispreferably has an aperture therein and each of the inserts preferably includes projections riveted through the acetabulum aperture for holding the inserts inposition.

As here embodied, the artificial hip joint also preferably includes an enlarged shoulder integral with and between the pin and the neck, the neck having a base joined at the shoulder and eccentrically positioned with respect to the central axis of the pin. Preferably, a portion of the neck extends upwardly from the shoulder and in a continuous manner from a side portion of the shoulder.

It is to be understood, of course, that both the fore going general description and the following detailed description are explanatory only and are not restrictive of the invention.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate a preferred embodiment of the invention, and together with the description, serve to explain the principles of the invention.

FIG. 1 is an elevation view, partially in section, of the artificial hip joint of this invention;

FIG. 2 is a view taken on the line 2--2 of FIG. 1 and looking in the direction of the arrows;

FIG. 3 is a view taken on the line 33 of FIG. 1 and looking in the direction of the arrows;

FIG. 4 is a sectional view taken on the line 44 of FIG. 1 and looking in the direction of the arrows;

FIG. 5 is an exploded perspective view of the artifi cial hip; and

FIG. 6 is a fragmentary sectional view of a portion of the artificial hip illustrating the method of assembly.

With reference now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown a machined acetabulum prosthesis 10 of the cotyloid cavity defining a socket l2 and having a plurality of blades 14, I6, 18, and 20 extending outwardly from the socket for engaging the prepared wall (not shown) of the cotyloid cavity.

A machined prosthesis 22 of the head of the femur is movably interconnected with acetabulum prosthesis 10 and includes a pin 24 to be driven into the bonemarrow channel of the femur (not shown), a curved neck 26 integral with pin 24 and a hip ball 28 fixedly positioned, e.g. by shrinking, on the neck and movably located within socket 12.

As here embodied, acetabulum prosthesis 10 includes two inserts 30, and each of the inserts has a surface area in contacting relationship with hip ball 28. The combined surface areas of the inserts contact hip ball 28 over a total of more than one-half the spherical surface area of the ball.

Each of inserts 30 includes a projection 32 that fits through an aperture 34 located in acetabulum prosthesis 10. In manufacturing the artificial hip joint, inserts 30 are positioned around hip ball 28, and projections 32 are then inserted through aperture 34. The projections are then hammered down or riveted and polished to be flush with the upper surface 36 of prosthesis 10.

The acetabulum prosthesis 10 preferably has four second plurality of notches 42 and a second plurality of holes 44 alternately positioned with respect to notches 42.

Third blade 18 extends around and exteriorly of socket l2 and is provided with a plurality of depressions 46 and with a third plurality of notches 48 alternately positioned with respect to the depressions. A

fourth blade 20 is also provided and similarly extends around and exteriorly of socket 12. Blade 20 is provided with a pluraity of indentations 50, and holes 40 and 44, notches 38, 42 and 48 together with depressions 46 and indentations 50 assist in holding acetabulum prosthesis in position within the hip and enable tissue and bone growth to extend through the holes to firmly affix prosthesis 10 in the desired position.

Each of blades l4, 16, 18, and also defines a respective flat lower face 52, 54, 56, and 58, and each of these faces is positioned in parallel relationship with the others. This face configuration of the blades is important in enabling the blades to be embedded into the bone of the natural cotyloid cavity. Each of the notches prosthesis 10 together with the apertures located in the blades that enable the prosthesis to be fixedly positioned within the prepared cotyloid cavity of the pelvis. The configuration ofprosthesis 10 also permits the growth of bonetissue through the holes in the blades in such a way as to hold the prosthesis in position within the pelvis in a firm and lasting manner.

Prosthesis 22 of the head of the femur, in addition to pin 24 and neck 26, also preferably includes an enlarged shoulder 60 integral with and positioned between the pinand the neck, and the neck is preferably formed with a base 62 joined to the shoulder and eccentrically positioned with respect to the central axis 64 of the pin. Shoulder 60 defines a side portion 66 and a lower surface 68, and it is surface 68 that rests on the upper portion of the severed femur when the artificial hip joint is installed. In a preferred construction of the artificial hip joint, an innermost portion 70 of the neck also extends in a continuous manner from side portion 62 of the shoulder.

It is also preferable and the preferred embodiment illustrated provides for a curvature of neck.26 so as to form an angle of substantially 130 with pin axis 64. The angle is measured between the pin axis and an imaginary line passing from the pin axis through the center of hipball 28 and tangentially to the innermost curved surface 70 of the neck.

Pin 24 also defines two slots 72 and 74 opening in directions parallel to the direction of curvature of neck 26. The function of these slots is similar to the function of the holes in prosthesis l0, and slots 72 and 74 permit bone tissue to grow therethrough so as to fix pin 24 and prosthesis 22 within the femur. Pin 24 is also tapered away fromneck 26, and the neck is tapered away from the pin. The taper of the pin permits it to be driven downwardly and into the bone-marrow channel of the femur.

In an alternative arrangement and use of the artificial hip joint of this invention, shoulder 60 is provided with a hole 76 entering the side portion 66 of the shoulder. A rod 78 is also provided, and it is adapted to pass through a hole drilled in the greater trochanter (not shown) and to be driven into hole 76 to hold the of the femur and for providing additional support for the artificial hip on the femur when necessary. The collar is provided with a flange portion 82 for engaging the lower surface 68 of shoulder 60, and the collar is also provided with a sleeve portion 84 integral with flange portion 82 for sliding over pin 24 so that the collar can be positioned on the upper part of the severed femur. Pin 24. can, thus, be inserted through the collar and into the bone-marrow channel of the femur to cause shoulder 60 torest on flange portion 82.

It is also preferable that sleeve portion 84 of the collar be provided with a plurality of holes 86 for enabling bone tissue to grow through the holes and to assist in holding the collar in its proper position on the femur.

Another important feature of this invention is the composition of the artificial hip joint and particularly the preferred use of cobalt alloy for the hip ball and for the inserts together with the use of titanium or a titanium alloy for the remaining portions of the joint. This combination of materials has proven to be highly effective in providing the desired strength for the hip joint while also providing for the desired resistance to corrosion. The use of cobalt alloy for the hip ball inserts does not result in galvanic action with the titanium or titanium alloy of the remainder of the joint, and the cobalt alloy provides the desired resistance to scoring necessary because of the frictional contact between the hip ball and the inserts. The metals or alloys utilized in forming the hip joint are preferably constituted of surgical grade materials.

In a preferred embodiment, both inserts 30 and hip ball 28 are comprised by weight of cobalt 65 percent, chromium 30 percent, and molybdenum 5 percent. The remaining portions of the joint are preferably comprised of titanium or a titanium alloy. The titanium is preferably a commercially pure metal having a 0.2 percent offset yield strength of 50,000 psi and sold under the tradename RMI 50 by Reactive Metals, Inc.,

Niles, Ohio. The titanium alloy preferably comprises by gouge and is moved upwardly together with the asso-.

ciated muscles. The hip bone or upper portion of the femur is then cut by a saw or gouge at the level of the lower edge of the trochanter minor. The head of the femur is then removed together with the neck and the intertrachanter region with the help of grooved gouges.

The bone-marrow channel of the femur is then worked by special conical milling cutters, the size of which is predetermined exactly with respect to the size of prosthesis pin 24. The bone-marrow channel of the femur is preferably reamed to a size that corresponds exactly to the size of pin 24. The natural cotyloid cavity is also worked with mushroom milling cutters, and the size of the biggest cutter should be 2-3 mm smaller in diameter than that of the outer dimensions of acetabulum prosthesis of the cotyloid cavity. This is necessary to ensure a reliable attachment of prosthesis 10 to the bones of the pelvis.

After the natural cotyloid cavity of the pelvis has been properly prepared, prosthesis pin 24 is driven into the bone-marrow channel of the femur. One-half of acetabulum prosthesis 10 is then inserted into the prepared cotyloid cavity of the pelvis in such a way as to have blades 14, l6, l8, and 20 substantially perpendicular to the plane (not shown) joining the outside edges of the natural cotyloid cavity (not shown). Prosthesis 10 is then pressed into the natural cotyloid cavity with the help of a special tap and is gradually turned until the edges of largest blade 14 sink evenly 2-5 mm into the prepared natural cotyloid cavity walls. Prosthesis 10 cuts into the bones of the natural cotyloid cavity, and thereby ensures reliable attachment of .prosthesis 10 to the bones making up the natural cotyloid cavity.

The previously severed trochanter major is then fastened by means of rod 78 to the outside surface of the upper end of the femur. A small hole 76' is provided in shoulder 60 of the prosthesis for this purpose and a hole is also drilled through the trochanter major so that rod 78 can pass through the hole in the trochanter major to be inserted into hole 76. The incision is then sutured together and postoperative procedures are then followed to avoid postoperative shock.

The holes provided in acetabulum prosthesis l0 and the slots provided in prosthesis 22 are intended for the growth of bonetissue into them as a result of the mechanical irritationof the bones caused by the operation, and such bone growth does occur to firmly hold the prostheses in position.

The present invention, thus, provides for an extremely strong and durable artificial hip joint that is highly resistive to corrosion and to other adverse actions within the human body. The joint is extremely versatile and is capable of performing all functions inherent in a normal human hip joint. The joint also advantageously relies on bone tissue growth stimulated by insertion of the artificial joint to strongly affix the prostheses of the joint in place.

The invention in its broader aspects is not limited to the specific details described, and departures may be made from such details without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. An artificial hip joint, comprising:

an acetabulum prosthesis of the cotyloid cavity defin ing a socket and having a plurality of blades extending downwardly away from the socket fora prosthesis of the head of the femur movably interconnected with said acetabulum prosthesis and including a pin to be driven into the bone-marrow channel of the femur, a curved neck integral with the pin, and a hip ball fixedly positioned on the neck and movably located within said socket, the socket enveloping more than one-half of the hip ball to prevent withdrawal of the hip ball from the socket.

2. An artificial hip as in claim 1 further including:

a first blade extending around and exteriorly of the socket and having a first plurality of notches in the first blade and a first plurality of said holes alternately positioned in the first blade with respect to the notches;

a second blade extending around and exteriorly of the socket and having a second plurality of notches in the second blade and a second plurality of said holes alternately positioned in the second blade with respect to said last-mentioned notches;

a third blade extending around and exteriorly of the socket and having a plurality of depressions in the third blade and a third plurality 'of notches alternately positioned in the third blade with respect to said depressions; and

a fourth blade extending around and exteriorly of the socket and having a plurality of indentations in the fourth blade, whereby the notches, depressions, and indentations aid in holding the acetabulum prosthesis in position.

3. An artificial hip joint as in claim 1 wherein the curvature of the neck is such as to form an angle of substantially l30 with the axis of the pin, wherein the angle is measured between the pin axis and an imaginary line passing from the pin axis-through the center of the hip ball and tangentially to the innermost curved surface of the neck.

4. An artificial hip as in claim 1 wherein the blades are located with the edges thereof in imaginary parallel planes.

5. An artificial hip as in claim 1 wherein each of said blades has a plurality of spaced notches formed therein.

6. An artificial hip as in claim 5 wherein each of said notches is V-shaped and defines an angle of 30.

7. An artificial hip as in claim 1 wherein said acetabulum prosthesis further includes at least one insert connected to form said socket for movably receiving said hip ball.

8. An artificial hip as in claim 7 wherein said acetabulum prothesis further includes two of said inserts, each of said inserts having a surface area for contacting said hip ball over more than one-fourth the spherical surface area of said ball.

9. An artificial hip as in claim 8 wherein said acetabulum prosthesis has an aperture therein and wherein said inserts each include projections riveted through said aperture.

10. An artificial hip as in claim 8 wherein said inserts are comprised by weight of Cobalt 65 percent, Chromium 30 percent, and Molybdenum 5 percent.

11. An artificial hip as in claim 1 wherein said hip ball is comprised by weight of Cobalt 65 percent, Chromium 30 percent, and Molybdenum 5 percent.

12. An artificial hip as in claim 11 wherein the blades of said acetabulum prosthesis and all of the prosthesis of the head of the femur but the hip ball are comprised of titanium or a titanium alloy.

13. An artificial hip as in claim 12 wherein the titanium alloy is RMI 6 Al-4V.

14. An artificial hip as in claim 12 wherein the ,titanium is RMI 50.

15. An artificial hip as in claim 1 further including:

an enlarged shoulder integral with and between the pin and the neck;

said neck having a base joined to the shoulder and eccentrically positioned with respect to the central axis of the pin.

16. An artificial hip as in claim 1 further including:

an enlarged shoulder integral with'and between the pin and the neck, a portion of the neck extending in a continuous manner from a side portion of the shoulder.

18. An artificial hip as in claim 1 further including:

an enlarged shoulder integral with and between the pin and the neck; and

a collar, having a flange portion for engaging the underside of said shoulder and a sleeve portion integral with the flange portion slid over said pin whereby the collar can be positioned in the upper part of the femur when the pin is inserted into the bone-marrow channel of the femur causing the shoulder to rest on the flange portion.

19. An artificial hip as in claim 18 wherein said sleeve portion defines a plurality of holes for enabling bone tissue to grow therethrough to hold the collar in position on the femur.

20. An artificial hip as in claim 18 wherein said collar is comprised of titanium or a titanium alloy.

21. An artificial hip as in claim 1 wherein the pin defines two slots opening in directions parallel to the direction of curvature of said neck.

22. An artificial hip as in claim 1 wherein the pin is tapered away from the neck and wherein the neck is tapered away from the pin.

' 23. An artificial hip joint comprising:

an acetabulum prosthesis of the cotyloid cavity defining a chamber and having two inserts fixedly positioned within the chamberffor forming a socket, said acetabulum prosthesis having an aperture therein and said inserts each having means extending through said aperture for holding the inserts in place; and

a prosthesis of the head of the femur movably interconnected with said acetabulum prosthesis and including a pin to be driven into the bone-marrow channel of the femur, a curved neck integral with the pin, and a hip ball fixedly positioned on the neck and movably located within said socket, the socket enveloping more than one-half of the hip ball to prevent withdrawal of the hip ball from the socket.

24.- An artificial hip joint as in claim 23 wherein said means comprises a projection for fastening through said aperture and for holding the inserts in position.

25. An artificial hip joint as in claim 24 wherein said projections are riveted through said aperture.

26. An artificial hip joint as in claim 23 wherein the curvature of the neck is such as to form an angle of substantially 130 with the axis of the pin, wherein the angle is measured between the pin axis and an imaginary line passing from the pin axis through the center of the hip ball and tangentially to the innermost curved surface of the neck.

27. An artificial hip joint as in claim 23 wherein said acetabulum prosthesis includes a plurality of blades extending outwardly away from thechamber for engaging the prepared wall of the cotyloid cavity and wherein each of said blades defines a fiat lower face, each of said faces positioned in parallel relationship with each other.

28. An artificial hip joint as in claim 27 wherein said insert and the hip ball are comprised by weight of Cobalt 65 percent, Chromium 30 percent, and Molybdenum 5 percent.

29. An artificial hip joint as in claim 28 wherein the v blades of said acetabulum prosthesis and all of the prosthesis of the head of the femur but the hip ball are comprised of titanium or a titanium alloy.

30. An artificial hip joint as in claim 29 wherein the titanium alloy is RMI 6Al-4V.

31. An artificial hip joint as in claim 29 wherein the titanium is RMI 50.

32. An artificial hip joint as in claim 23 further including:

an enlarged shoulder integral with and between the pin and the neck;

said neck having a base joined to the shoulder and eccentrically positioned with respect to the central axis of the pin.

33. An artificial hip joint as in claim 32 wherein a portion of the neck extends in a continuous manner from a side portion of the shoulder. V

34. An artificial joint, comprising:

a first prosthesis having a bearing insert defining a socket, a second prosthesis movably interconnected with said first prosthesis and including a pin to be driven into a bone-marrow channel, a neck integral with the pin, and a ball fixedly positioned on the neck and movably located within said socket, said ball and said bearing insert being made from a cobalt alloy and the remainder of said joint from titanium or a titanium alloy, said metals or alloys being of a surgical grade.

35. An artificial joint as in claim 34 wherein the cobalt alloy is a cobalt-chromium alloy.

36. An artificial joint as in claim 34 wherein the cobalt alloy contains cobalt, chromium and molybdenum.

37. An artificial joint as in claim 34 wherein the cobalt alloy comprises by weight approximately 65 percent cobalt, 30 percent chromium and 5 percent molybdenum.

38. An artificial joint as in claim 34 wherein the titanium alloy comprises by weight approximately percent titanium, 6 percent aluminum and 4 percent vanadium.

39. An artificial joint as in claim 34 wherein the joint is a hip joint, the first prosthesis is an acetabulum prosthesis of the cotyloid cavity and the second prosthesis is a prosthesis of the head of the femur.

40. An artificial joint as in claim 39 wherein the socket envelops more than one-half of the hip ball to prevent withdrawal of the hip ball from the socket.

41. An artificial joint as in claim 40 wherein the acetabulum prosthesis has a plurality of blades extending outwardly away from the socket for engaging the prepared wall of the cotyloid cavity, predetermined ones of said blades having holes therein for enabling growth of the bone tissue therethrough and around the blades for holding the acetabulum prosthesis in position.

42. An artificial joint as in claim 41 wherein the blades are located with the edges thereof in imaginary parallel planes.

43. An artificial joint as in claim 42 wherein each of said blades defines a fiat lower face and wherein each of said faces is positioned parallel with each other.

44. An artificial joint as in claim 42 wherein each of said blades defines an angle of 30.

45. An artificial joint as in claim 39 wherein said acetabulum prosthesis further includes two of said bearing inserts, each of said bearing inserts having a surface area for contacting said hip ball over more than onefourth of the spherical surface area of said ball.

46. An artificial joint as in claim 45 wherein said acetabulum prosthesis has an aperture therein and wherein said bearing inserts each includes means extending through said aperture for holding the inserts in place.

47. An artificial joint as in claim 41 further including:

a first blade extending around and exteriorly of the socket and having a first plurality of notches in the first blade and a first plurality of said holes alternately positioned in the first blade with respect to the notches;

a second blade extending around and exteriorly of the socket and having a second plurality of notches in the second blade and a second plurality of said holes alternately positioned in the second blade with respect to said last-mentioned a third blade extending around and exteriorly of the socket and having a plurality of depressions in the third blade and a third plurality of notches alternately positioned in the third blade with respect to said depressions; and

a fourth blade extending around and exteriorly of the socket and having a plurality of indentations in the fourth blade, whereby the notches, depressions, and indentations aid in holding the acetabulum prosthesis in position.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3,820,167 I Q DATED June 28, 1974 INVENTOR(S) KONSTANTIN M. SIVASH It is certified that error appears in the above-identified patent and that 'said Letters Patent are hereby corrected as shown below:

Claim 1, line 4: change "downwardly" to outwardly Signccl and Scaled this Twenty-first D3) f September 1976 [SEAL] Arrest:

. RUTH C. MASON C. MARSHALL DANN Arresting Officer (ummissiuner oj'l arenrs and Trademarks 

